THIS AVALANCHE ADVISORY EXPIRED ON March 16, 2017 @ 6:56 am
Avalanche Advisory published on March 15, 2017 @ 6:56 am
Issued by Brandon Schwartz - Tahoe National Forest

LOW avalanche danger exists today for all elevations. The rate of snow surface melt is expected to be slower today as compared to the past several days. Loose wet avalanches may still occur today, but instability is expected to be less widespread than earlier this week. Avoid travel on or below steep slopes with wet snow and no supportable surface crust.

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Loose Wet
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  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Air temperatures remained above freezing again last night with air temperatures just prior to sunrise at most locations above the valley floors in the upper 30s to mid 40s. Generally clear skies last night are expected to have allowed for some thin but supportable snow surface refreeze in open areas from radiational cooling. Areas under forest canopy are likely to have had little to no overnight refreeze. Increasing cloud cover today along with increasing SW winds are expected to slow the rate of snow surface melt as compared to recent days. Loose wet avalanche problems could still develop today, but may hold off until the afternoon hours. Wet snow instability is also expected to be less widespread today than over the past few days.

The degree of today's loose wet avalanche problem will be highly dependent on how fast significant cloud cover materializes. Loose wet avalanches could still occur at all elevations and on all aspects, especially if cloud cover is slow to arrive. Avoid travel on or below steep slopes with wet snow and no supportable surface crust.

recent observations

Observations were made yesterday on Stevens Peak (Carson Pass area). Variable amounts of snow surface refreeze existed during the morning hours. Little to no refreeze had occurred under forest canopy. Thin but supportable snow surface refreeze lasting through the late morning hours had occurred on open slopes with a notably better refreeze above 8,200' than below 8,200'.

Additional hazards in the form of opening glide cracks and cornice collapses have been noted around the forecast area during this recent warm spell. Glide cracks releasing as glide avalanches and cornice collapse events have very low predictability. It is recommended to avoid areas below glide cracks and large cornice features during any warm spell.

Weather and CURRENT CONDITIONS
weather summary

A weather system passing to the north of the forecast area will bring increasing cloud cover and wind to the region today. Ridgetop winds out of the SW increased to moderate speed yesterday but have not been able to fully mix out the air temperature inversion. Winds are further forecast to increase to strong in speed this afternoon. Very light showers are possible over the northern portion of the forecast area tonight into tomorrow morning with snow level around 8,000' or higher. High pressure builds over the region tomorrow for decreasing cloud cover and gradually decreasing wind speeds.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 37 to 42 deg. F.
Max. temperature in the last 24 hours: 50 to 56 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 31 mph
Maximum wind gust in the last 24 hours: 47 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 122 to 176 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy skies, becoming mostly cloudy. Mostly cloudy skies. Isolated showers after midnight over the northern portion of the forecast area. Mostly cloudy skies, becoming partly cloudy. Isolated showers in the morning over the northern portion of the forecast area.
Temperatures: 51 to 57 deg. F. 31 to 37 deg. F. 50 to 56 deg. F.
Wind Direction: SW SW SW
Wind Speed: 15 to 25 mph. Gusts up to 35 mph increasing to 50 mph in the afternoon. 15 to 25 mph. Gusts to 55 mph decreasing to 45 mph after midnight. 10 to 15 mph. Gusts to 40 mph decreasing to 30 mph in the afternoon.
Expected snowfall: 0 in. 0 to trace in. 0 to trace in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy skies, becoming mostly cloudy. Mostly cloudy skies. Isolated showers after midnight over the northern portion of the forecast area. Mostly cloudy skies, becoming partly cloudy. Isolated showers in the morning over the northern portion of the forecast area.
Temperatures: 45 to 51 deg. F. 31 to 36 deg. F. 45 to 51 deg. F.
Wind Direction: SW SW SW
Wind Speed: 20 to 35 mph. Gusts to 50 mph increasing to 70 mph in the afternoon. 30 to 40 mph with gusts to 85 mph, decreasing to 20 to 35 mph with gusts to 75 mph after midnight. 20 to 35 mph. Gusts to 75 mph decreasing to 50 mph in the afternoon.
Expected snowfall: 0 in. 0 to trace in. 0 to trace in.
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258